JPH11232662A - Method for reading recorded information and apparatus for reproducing recorded information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reading recorded information and an apparatus for reproducing recorded information whereby information can be reproduced at high speed from a recording medium. SOLUTION: When information data read by an information read means which reads recorded information simultaneously from each of N record tracks (N is an integer not smaller than 2) include a relatively small count of read errors, a read operation corresponding to one rotation of a disk and a jump operation by (N-1) tracks are alternately repeatedly carried out by the information read means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recorded information reproducing apparatus for reproducing recorded information from a recording medium.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a recorded information reproducing method and a recorded information reproducing apparatus capable of reproducing information data from a recording disk on which the information data is recorded at higher speed and with higher accuracy.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for reading recorded information in a recorded information reproducing apparatus capable of reproducing recorded information from a recording disk at high speed and with high accuracy.

[0004]

According to a first aspect of the present invention, there is provided a method for reading recorded information in a recorded information reproducing apparatus for reproducing recorded information recorded on a recording disk to obtain reproduced information data. Wherein the recording information reproducing apparatus simultaneously reads the recording information from each of N (N is an integer of 2 or more) recording tracks formed on the recording disk to obtain N reading signals. Information reading means, and an error correcting means for detecting an error occurring in the read signal and correcting the error to obtain the reproduction information data, and when the error is small, the information reading means The reading operation for one rotation of the disk and (N-
1) The track jump operation is alternately and repeatedly executed.

The recorded information reading method according to the second aspect of the present invention is characterized in that, when the error is large, the information reading means performs a reading operation for one rotation of the disk and a track jump operation of (N-2) or less. Is executed alternately and repeatedly. or,
A recording information reading method according to a third aspect of the present invention is a recording information reading method for a recording information reproducing apparatus for obtaining reproduction information data by reproducing recording information recorded on a recording disk, wherein the recording information reproducing apparatus Is information reading means for simultaneously reading recording information from each of N (N is an integer of 2 or more) recording tracks formed on the recording disk to obtain N reading signals; Error correction means for detecting an error that has occurred and correcting the error to obtain the reproduction information data, obtaining a data error rate in the read signal, wherein the data error rate is higher than a predetermined error rate. Is smaller, the information reading means repeats the information reading operation for one rotation of the disk up to one disk radius line and the (N-1) track jump operation. To.

A recorded information reading method according to a fourth aspect of the present invention is a recorded information reading method for a recorded information reproducing apparatus for reproducing recorded information recorded on a recording disk to obtain reproduced information data. The recorded information reproducing device,
Information reading means for simultaneously reading recorded information from each of N (N is an integer of 2 or more) recording tracks formed on the recording disk to obtain N read signals; Error correction means for detecting an error and correcting the error as the reproduction information data, obtaining a data error rate in the read signal, wherein the data error rate is smaller than a predetermined error rate. In this case, the information read operation and the (N-1) track jump operation are alternately and repeatedly performed until the read signal already read before one rotation of the disk is read again, and the data error rate is higher than the predetermined error rate. Is large, the information read operation until the read signal already read before one rotation of the disk is read again and the track jump operation below (N-2) are alternately and repeatedly executed. That.

In the recording information reading method according to a fifth aspect of the present invention, the error detection is a random error detection, and the error correction means includes a line length burst corresponding to a data error rate in the read signal. Correct the error. or,
A recording information reproducing apparatus according to a sixth aspect of the present invention is a recording information reproducing apparatus that reproduces recording information recorded on a recording disk to obtain reproduction information data, wherein the N information is formed on the recording disk. The recording information is simultaneously read from each of the recording tracks (N is an integer of 2 or more) and N
An information reading means for obtaining a read signal of the book; an error correcting means for detecting an error occurring in the read signal and obtaining an error-corrected error as the reproduced information data; And a control unit for alternately and repeatedly executing a reading operation for one rotation of the disk by the reading unit and a (N-1) track jump operation.

Further, in the recording information reproducing apparatus according to a seventh aspect of the present invention, when the number of errors is large, the control means may perform a reading operation for one rotation of the disk by the information reading means and (N-2) And the track jump operation are alternately and repeatedly executed. A recording information reproducing apparatus according to an eighth aspect of the present invention is a recording information reproducing apparatus for reproducing recording information recorded on a recording disk to obtain reproduction information data, wherein the recording information reproducing apparatus is formed on the recording disk. N books (N is 2
An information reading means for simultaneously reading recorded information from each of the recording tracks of the above (integer) to obtain N read signals; and detecting and correcting an error occurring in the read signal and reproducing the error. Error correcting means for obtaining information data, error rate measuring means for obtaining a data error rate in the read signal, and one disk radius by the information reading means when the data error rate is smaller than a predetermined error rate. And a control means for alternately and repeatedly executing an information reading operation for one rotation of the disk up to the line and an (N-1) track jump operation.

According to a ninth aspect of the present invention, there is provided a recorded information reproducing apparatus which reproduces recorded information recorded on a recording disk to obtain reproduced information data. N formed (N is 2
An information reading means for simultaneously reading recorded information from each of the recording tracks of the above (integer) to obtain N read signals; and detecting and correcting an error occurring in the read signal and reproducing the error. Error correction means for obtaining information data, error rate measurement means for obtaining a data error rate in the read signal, and when the data error rate is smaller than a predetermined error rate, the data has been read before one revolution of the disk. The information reading operation until the read signal is read again and (N
-1) While the track jump operation is alternately repeated, if the data error rate is larger than a predetermined error rate, an information reading operation until a read signal already read before one rotation of the disk is read again is read. And a control means for alternately and repeatedly executing the track jump operation described below.

[0010] In the recording information reproducing apparatus according to a tenth feature of the present invention, the error detection is a random error detection,
The error correction means corrects a burst error of a line length corresponding to a data error rate in the read signal.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. (First Embodiment) FIG. 1 is a diagram showing a configuration of a recorded information reproducing apparatus for reproducing recorded information from a recording disk based on a recorded information reading method according to a first embodiment of the present invention.

In FIG. 1, a laser beam emitted from a laser oscillator 103 mounted on a pickup 100 is split via a grating 104 into three information reading beams. These three information reading beams are
Via a half mirror 105 and an objective lens 106, for example, a DVD (digital versatile disk), a CD and an LD
Irradiation is performed on the recording surface of the recording disk 23 as shown in FIG. Each of these three information reading beams is applied to a recording disk 23.
Irradiate three recording tracks adjacent to each other on the recording surface. Incidentally, originally, the recording disk 23 includes:
Although one recording track is formed in a spiral shape, in the present embodiment, this one recording track will be described as one track per one rotation of the disk.

The above three information reading beams are used to irradiate 3
Light reflected from each of the recording tracks of the book is passed through an objective lens 106 and a half mirror 105, respectively, to a photodetector 107.
Is derived. The photodetector 107 includes independent photodetectors 107a to 107c. The photodetector 107b is
The reflected light from the central recording track among the three recording tracks is received via the half mirror 105, and the read signal Rb obtained by photoelectrically converting the reflected light is supplied to the information data demodulation circuit 24b. The photodetector 107a receives reflected light from a recording track adjacent to one side of the central recording track via the half mirror 105, and demodulates a read signal Ra obtained by photoelectrically converting the received signal to information data. The signal is supplied to the circuit 24a. The photodetector 107c receives reflected light from a recording track adjacent to the other side of the center recording track via the half mirror 105, and demodulates a read signal Rc obtained by photoelectrically converting the received light. Circuit 2
4c.

With the configuration described above, the pickup 100 as information reading means simultaneously reads recorded information from each of three recording tracks adjacent to each other on the recording disk 23, and performs three readings corresponding to each recording track. The signals Ra to Rc are obtained. The information data demodulation circuit 24a converts the read signal Ra into a binary digital signal, restores the original information data by demodulating it, and supplies it to the data memory 26a. The data memory 26a sequentially writes and stores the demodulated information data. Also, the data memory 26a stores the CP
In accordance with the read command signal RDa supplied from U32, the information data stored as described above is sequentially read and supplied to the error correction circuit 29. Information data demodulation circuit 24b
Converts the read signal Rb into a binary digital signal, restores the original information data by demodulating it, and supplies it to the data memory 26b. The data memory 26b sequentially writes and stores the demodulated information data. The data memory 26b sequentially reads out the information data stored as described above in accordance with the read command signal RDb supplied from the CPU 32, and supplies this to the error correction circuit 29. The information data demodulation circuit 24c converts the read signal Rc into a binary digital signal, demodulates the signal, restores the original information data, and supplies it to the data memory 26c. The data memory 26c sequentially writes and stores the demodulated information data.
Further, the data memory 26c sequentially reads out the information data stored as described above in accordance with the read command signal RDc supplied from the CPU 32, and supplies this to the error correction circuit 29.

The error correction circuit 29 is provided in the data memory 2
Error detection is performed on the information data read from 6a to 26c using one code block, for example, an ECC block composed of 16 sectors (32 Kbytes) as one unit. At this time, when an error is detected in each bit in the information data, the error correction circuit 29 generates an error detection signal ER for each bit in which the error is detected, and outputs this to the CPU.
It is sent out on the bus 30. Further, the error correction circuit 29 performs an error correction process on the information data according to the error detection result, and outputs this as reproduction information data.

The spindle motor 22 has a CPU bus 30
The recording disk 23 is driven to rotate in the rotation direction according to the forward rotation command signal or the reverse rotation command signal supplied via the recording disk 23. The slider mechanism 28 moves the pickup 100 in the disk radial direction in response to a read start position signal or a track jump command signal supplied via the CPU bus 30.

The pulse generator 35 includes a spindle motor 2
The CPU 3 generates a pulse signal including a number of pulses synchronized with the rotation of the disk 2 (that is, the rotation of the disk 23) (hereinafter referred to as 36 pulses per rotation of the disk 23).
Feed to 2. The CPU bus 30 has a ROM (Read Only Memory) 31 preliminarily storing software based on the recorded information reproducing method according to the present invention, and transmits various command signals as described above in accordance with the software.
CPU (Central Processing Unit) that sends out data to 0 and controls playback
32, a RAM (random access memory) 33, and an operation device 3 for receiving various operation commands from a user
4 are connected.

Hereinafter, an information reproducing operation performed by the above configuration will be described. FIG. 2 shows the ROM 31
CPU 32 based on software stored in
FIG. 4 is a diagram showing a flow of a reproducing operation subroutine executed by the CPU. When the CPU 32 receives a reproduction start command and its reproduction start address from the operation device 34 during execution of the main flow (not described), the CPU 32 shifts to execution of a reproduction operation subroutine as shown in FIG.

First, the CPU 32 stores the reproduction start address as RA in a built-in register (step S).
1). Next, the CPU 32 sets the reproduction start address RA
Pickup 10 at a position on the disk indicated by
A reading start position signal for transferring 0 is supplied to the spindle motor 22 and the slider mechanism 28 via the CPU bus 30 (step S3). The slider mechanism 28 transfers the pickup 100 to a position on the disk indicated by the reading start position signal.

Next, the CPU 32 supplies a normal rotation command signal to the spindle motor 22 via the CPU bus 30 in order to start the information reading operation from the reading start position. Further, each time the pickup 100 completes reading of one rotation of the disk, the CPU 32 reads the read command signal RD.
a to RDc by switching each of the data memories 26a to 26c
Supply to each. Further, the CPU 32 resets the value of a counter CNT for counting the number of pulses supplied from the pulse generator 35 to 0 (step S4). By executing the step S4, the pickup 100
Starts an information reading operation from the reading start position. At this time, the read signals Ra to Rc simultaneously read from each of the three recording tracks are read by the information data demodulation circuits 24a to 24c, respectively.
c. These information data demodulation circuits 24a to 24a
Each of the information data demodulated by c is written to each of the data memories 26a to 26c. Here, each of the data memories 26a to 26c has a pickup 100
Each time the reading of one rotation of the disk is completed, the reading state is alternately set. Thereby, the data memories 26a to 26a
The information data for each recording track divided and written into each of the recording tracks 26c is connected to the error correction circuit 29 according to the recorded form. The error correction circuit 29 performs error detection on the supplied information data, generates an error detection signal ER every time an error bit is detected in any one of the data memories 26a to 26c, and outputs this to the CP.
It is sent out on the U bus 30. Further, the error correction circuit 29
The corrected error bit is output as reproduction information data.

In parallel with the start of the reading operation, the CPU 32 starts counting the number of pulses supplied from the pulse generator 35 while the pickup 100 is at the reading start position. Next, the CPU 32 determines whether or not 36 pulses for one rotation of the disk have been counted from the state where the pickup 100 is located at the reproduction start address RA, that is, the counter C
The counter C determines whether or not NT has reached 36.
The process is executed until the value of NT reaches 36 (step S5).
Next, the CPU 32 resets the counter CNT to 0 (Step S6).

Next, the CPU 32 counts the number of the error detection signals ER over a predetermined period, and based on the number of the error detection signals ER per code block in the information data read within the predetermined period. The error rate is obtained and stored in the built-in register as the error rate X (step S
7). Next, the CPU 32 determines whether or not the error rate X is smaller than a predetermined error rate E1 (step S8). If it is determined in step S8 that the error rate X is smaller than the predetermined error rate E1, the CPU 3
2 supplies a track jump command for causing the pickup 100 to make a track jump by two tracks to the slider mechanism 28 via the CPU bus 30 (step S).
9). By executing the step S9, the slider mechanism 28 causes the pickup 100 to make a track jump by two tracks in the outer circumferential direction of the disk. Step S above
When the error rate X is lower than the predetermined error rate E1 by performing the operations according to 5 to S9, every time the pickup 100 makes one rotation, a two-track jump is performed on the same radius line as the reading operation start position RA. Can be done.

It should be noted that even during the execution period of step S5, the pick-up 100
The recording information is read from each of the recording tracks of the book. On the other hand, if it is determined in step S8 that the error rate X is larger than the predetermined error rate E1, the CPU
Step S10 is executed without executing the track jump.
Move to.

After the end of the track jump in step S9, the pickup 100 starts reading information again from this track jump destination. These steps S
After the execution of step 8 or S9, the CPU 32 determines whether or not a reproduction end command has been issued from the operation device 34 (step S10). If it is determined in step S10 that the reproduction end command has not been issued, the CPU
The step 32 returns to the execution of the step S5 and executes the above-mentioned operation again. On the other hand, when it is determined that the reproduction end command has been issued, the CPU 32 exits this reproduction operation subroutine and returns to the execution of the main routine.

The operation performed by executing the reproducing operation subroutine as shown in FIG. 2 will be described below. First, by performing steps S1 to S4 in FIG.
The information is transferred to a position on the disk indicated by A, and the information reading operation is started from this position. That is, the three photodetectors 107 a to 107 mounted on the pickup 100
7c, information can be read individually and simultaneously from each of the three recording tracks adjacent to each other.

Next, by executing steps S5 and S6,
The reading operation is performed until the pickup 100 makes one rotation on the same radius line as the reading operation start position RA.
Next, by executing step S7, the error rate X at the time of reading the information is measured. Here, the error rate X
But,

[0027]

If X <error rate E1, the operation of step S9 is performed. By executing step S9, the pickup 100 jumps two tracks in the outer circumferential direction of the disk. On the other hand, when the error rate X is

[0028]

## EQU2 ## If the error rate E1 <X, the track jump operation is not performed.
When the track jump is completed, the process returns to step S5 again to repeatedly execute the information reading operation and the track jump operation as described above.

FIGS. 3 and 4 are views showing the operation of the pickup 100 performed by executing the reproduction operation flow shown in FIG. First, as shown in FIG. 3A, the three photodetectors 107a to 107c mounted on the pickup 100 move from the position on the disk radius line DL to the recording tracks 10, 11, and 12, respectively. Start reading the recorded information data individually and simultaneously.

Here, as shown in FIG. 3 (b), the recording track 10, 1
When reading of the information data recorded in each of 1 and 12 is completed, the pickup 100 reaches the position on the disk radius line DL again. When the pickup 100 reaches the position on the disk radius line DL, it jumps two tracks in the disk outer peripheral direction. Since the recording disk 23 is rotating while the pickup 100 is jumping by two tracks, the jump destination of the pickup 100 is ahead of the disk radius line DL as shown in FIG. 3C. Position. From this position, the pickup 100 starts reading information data recorded on each of the recording tracks 13, 14, and 15.

Here, as shown in FIG. 4 (d), when the reading operation for one rotation of the disk is completed and the pickup 100 reaches the position on the disk radius line DL again, the pickup 100 Jump two tracks in the direction. Therefore, the recording track 13,
Each of the head sections 14 and 15, that is, the section indicated by oblique lines in the figure, is an information missing section where information is not read. Since the recording disk 23 is rotating while the pickup 100 is jumping by two tracks, the jump destination of the pickup 100 is ahead of the disk radius line DL as shown in FIG. Position. From this position, the pickup 100
Starts reading information data recorded on each of the recording tracks 16, 17, and 18.

Here, as shown in FIG. 4 (f), when the information reading for one rotation of the disk is completed and the pickup 100 reaches the position on the disk radius line DL again, the pickup 100 is Jump two tracks in the outer circumferential direction. Therefore, recording track 1
Each of the head sections 6, 17, and 18, ie, the section indicated by oblique lines in the figure, is an information missing section in which information is not read.

The information missing section indicated by the diagonal lines in FIGS. 4D to 4F is treated as a burst error in the error correction circuit 29 and is restored by the error correction processing. FIG. 5 shows the error rate X and the error correction circuit 29 in each case where the total burst error length per block is 0, 4, 6, or 8 lines of the ECC block.
FIG. 7 is a diagram showing a correspondence relationship between the error information and the error rate of the corrected information data after the error correction processing.

The four graphs B0, B4,
B6 and B8 show the case where the length of the burst error occurring in the information data output from the information data demodulation circuit 24 is the number of lines of the ECC block 0, 4, 6, and 8, respectively. . For example, the error rate X before error correction
Is "0.005", the intersection P of the burst error length with the graph B6 indicating the number of lines 6 is within the demodulation allowable range (the error rate after error correction is e- ²⁰ or less). On the other hand, the intersection Q with the graph B8 in which the length of the burst error indicates the number of lines 8 is outside the demodulation allowable range. That is, when the error rate X is "0.005", even if data for six lines is lost, the data for six lines that have been lost is substantially corrected by the error correction processing by the error correction circuit 29. It can be restored, but when the length of the burst error becomes 8 lines,
This indicates that this cannot be restored.

As shown in FIG. 5, if the error rate X at the time of reading information is smaller than the error rate E1, the error rate E1 is, for example, the total burst error length is equal to the number of lines of the ECC block of 8 Is an error rate that can be almost corrected by the error correction circuit 29. That is, if the length of each of the three information missing sections indicated by oblique lines in FIGS. 4D to 4F is smaller than the length corresponding to eight lines of the ECC block, Even if the section is not read, the record information is obtained by the error correction circuit 29.

As described above, when the read error rate X is smaller than the predetermined first error rate E1 as described above, the information reading operation for one rotation of the disk up to the disk radius line DL and the two-track jump are performed. By alternately and repeatedly executing the operation, the recording information is simultaneously read from three recording tracks. If the read error rate X is higher than the above-mentioned predetermined error rate E1, if a track jump is performed while information data is being read from the disk, the information missing section during that time cannot be corrected and the reproduced data cannot be reproduced. , A track jump is not performed.

However, in such a reading method, in an apparatus for simultaneously reading recorded information from a plurality of recording tracks by a plurality of information reading beams as in this embodiment, the merit of having a plurality of information reading beams is sufficient. Has not been utilized in The second embodiment shown below is made in view of such a point, and changes the number of jump tracks according to the read error rate.

(Second Embodiment) In this embodiment, a track jump is not performed on the same radius line as the reading start position RA every rotation as in the first embodiment, but is already performed before one rotation of the disk. When the information of the read recording track is read again, a track jump is performed.

FIG. 6 is a diagram showing the configuration of a recorded information reproducing apparatus for reproducing recorded information from a recording disk based on the recorded information reading method according to the second embodiment of the present invention. FIG.
In FIG. 7, the same components as those in FIG. The difference between FIG. 1 and FIG. 6 is that the address extraction means 25 and the reread detection circuit 27 are provided except for the pulse generator 35.

That is, the read signal obtained by the photodetector 107 is supplied to the information data demodulation circuit 24 and the address extraction circuit 25 as in FIG. The address extraction circuit 25 sequentially detects physical addresses on the disk from each of the read signals Ra, Rb and Rc, and uses them as current addresses ADa to ADc.
7 and the CPU bus 30.

When each of the current addresses ADa to ADc has been read before one rotation of the disk, the reread detection circuit 27 generates a reread detection signal AR and sends it to the CPU bus 30. To send to. Hereinafter, an information reproducing operation performed by such a configuration will be described. FIG. 7 is a diagram showing a reproduction operation subroutine flow executed by the CPU 32 based on the software stored in the ROM 31 of FIG.

Steps for performing the same operations as in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. First, similarly to FIG. 2, when the CPU 32 receives a reproduction start command and its reproduction start address from the operating device 34 during execution of the main flow, the CPU 32 transfers the pickup 100 to the reproduction start address RA and starts the information reading operation. (S1 to S4).

Next, the CPU 32 determines whether or not the re-read detection signal AR has been sent from the re-read detection circuit 27 onto the CPU bus 30.
The process is executed until the data is transmitted onto the U bus 30 (step S1).
1). Note that even during the execution period of step S11, the pickup 100 reads the recorded information from each of the three recording tracks on the recording disk 23.

Here, in step S11,
When it is determined that the re-read detection signal AR has been sent out on the CPU bus 30, the CPU 32 obtains an error rate in the information data read within a predetermined period in the same manner as in FIG. It is stored in a register (step 7). Next, the CPU 32 determines whether or not the error rate X is smaller than a predetermined error rate E1 (step S8). In step S8, the error rate X
Is smaller than the predetermined error rate E1,
The PU 32 issues a track jump command to cause the pickup 100 to jump the track by two tracks.
The power is supplied to the slider mechanism 28 via the U bus 30 (step S9). By executing the step S9, the slider mechanism 28 causes the pickup 100 to make a track jump by two tracks in the outer circumferential direction of the disk.

On the other hand, if it is determined in step S8 that the error rate X is larger than the predetermined error rate E1,
The CPU 32 issues a track jump command to cause the pickup 100 to make a track jump by one track, by C.
The data is supplied to the slider mechanism 28 via the PU bus 30 (step S13). By executing the step S13,
The slider mechanism 28 causes the pickup 100 to make a track jump by one track in the outer peripheral direction of the disk.

After the end of the track jump in step S9 or S13, the pickup 100 starts reading information again from this track jump destination. After the execution of step S9 or S13, the CPU 32 determines whether or not a reproduction end command has been issued from the operation device 34 as in FIG. 2 (step S10). If it is determined in step S10 that the reproduction end command has not been issued, the CPU 32 proceeds to step S11.
And the above-described operation is executed again. On the other hand, if it is determined that the reproduction end command has been issued,
U32 exits this reproduction operation subroutine and returns to the execution of the main routine.

FIGS. 8 and 9 show that the error rate X is

[0048]

FIG. 8 is a diagram showing the operation of the pickup 100 performed by executing the reproduction operation flow shown in FIG. 7 when the error rate E1 <X. First, as shown in FIG. 8A, three photodetectors 107 mounted on the pickup 100 are used.
In steps a to 107c, information data recorded on each of the recording tracks 10, 11, and 12 is individually and simultaneously read from the position on the disk radius line DL1.

Here, as shown in FIG. 8B, one rotation of the disk causes the photodetectors 107a and 107a to rotate.
When each of the heads 07b reads again the information of the leading portion of the recording track 11 and the recording track 12 which has been read before one rotation of the disk, the pickup 100 jumps two tracks in the outer peripheral direction of the disk. Pickup 10
The recording disk 23 can be used while 0 is jumping two tracks.
Since the is rotating, the jump destination of the pickup 100 is a position on the disk radius line DL2 which is more advanced in the reading direction than the disk radius line DL1 as shown in FIG. 8C. From this position, the pickup 100 starts reading information data recorded on each of the recording tracks 13, 14, and 15.

Here, as shown in FIG. 9D, one rotation of the disk causes the photodetectors 107a and 107a to rotate.
When each of the heads 07b reads again the information of the leading portions of the recording tracks 14 and 15 which have been read before one rotation of the disk, the pickup 100 jumps two tracks in the outer peripheral direction of the disk. Therefore, the head section of the recording track 13, that is, the section indicated by oblique lines in the drawing is an information missing section where information reading is not performed.
Since the recording disk 23 is rotating while the pickup 100 is jumping two tracks, the jump destination of the pickup 100 is the disk radius at the previous reading start position as shown in FIG. Line DL
2 Disk radius line DL3 advanced in the reading direction from above
It will be in the upper position. From this position, the pickup 100
Starts reading information data recorded on each of the recording tracks 16, 17, and 18.

Here, as shown in FIG. 9 (f), when the disk makes one rotation, the photodetectors 107a and 107
When each of the heads 07b reads the information of the leading portion of the recording track 17 and the recording track 18 already read before one rotation of the disk, the pickup 100 jumps two tracks in the outer peripheral direction of the disk. Therefore, recording track 1
The head section of No. 6, that is, the section indicated by oblique lines in the figure, is an information missing section where information reading is not performed.

9 (d) to 9 (f), the information missing section indicated by the diagonal lines is treated as a burst error in the error correction circuit 29, and is restored by the error correction processing. At this time, as shown in FIG. 5, if the error rate X at the time of reading information is smaller than this error rate E1, as shown in FIG. Even if the length is equivalent to the number of lines of the ECC block of 8, the error rate is such that the error correction circuit 29 can substantially correct the length.

That is, if the length of one information missing section indicated by oblique lines in FIGS. 9D to 9F is smaller than the length corresponding to eight lines of the ECC block, Even if the information is not read, the record information in the information missing section is obtained by the error correction circuit 29. As described above, when the read error rate X is smaller than the predetermined error rate E1 as described above, the disk 1
By repeatedly and alternately performing the information reading operation for one rotation of the disk until the recording track which has already been read before the rotation is read again and the two-track jump operation, the recording information can be simultaneously read from three recording tracks. Reading is performed.

FIGS. 10 and 11 show the error rate X
But,

[0055]

FIG. 8 is a diagram showing an operation of the pickup 100 performed by executing the reproduction operation flow shown in FIG. 7 when X> error rate E1. First, as shown in FIG. 10A, three photodetectors 10 mounted on the pickup 100 are used.
7a to 107c individually and simultaneously start reading information data recorded on the recording tracks 10, 11, and 12 from the position on the disk radius line DL1.

Here, as shown in FIG.
One rotation of the disk causes the photodetector 107b to
Recording track 12 already read before one rotation of the disk
When the information at the head of is read again, the pickup 100
Jumps one track in the outer circumferential direction of the disk. Since the recording disk 23 is rotating while the pickup 100 jumps one track, the pickup 100
As shown in FIG. 10C, the jump destination is a position on the disk radius line DL2 which has advanced in the reading direction beyond the disk radius line DL1. From this position, the pickup 100 moves the recording tracks 12, 13,.
And 14 starts reading information data recorded in each of them.

Here, as shown in FIG.
One rotation of the disk causes the photodetector 107b to
Recording track 14 already read before one rotation of disk
When the information at the head of is read again, the pickup 100
Jumps one track in the outer circumferential direction of the disk. still,
Since the recording disk 23 is rotating while the pickup 100 jumps one track, the pickup 1
As shown in FIG. 11E, the jump destination of 00 is a position on the disk radius line DL3 which has advanced in the reading direction from the disk radius line DL2 which is the previous reading start position. From this position, the pickup 100 starts reading information data recorded on each of the recording tracks 14, 15, and 16.

Here, as shown in FIG.
One rotation of the disk causes the photodetector 107b to
When the information of the head of the recording track 16 already read before one rotation of the disk is read again, the pickup 100
Jumps one track in the outer circumferential direction of the disk. As described above, when the read error rate X is larger than the error rate E1 as described above, the information reading operation for one rotation of the disk until the recording track that has been read before the rotation of the disk is read again is read. And the one-track jump operation are alternately and repeatedly executed, so that the recorded information is simultaneously read from three recording tracks.

In the information reading method shown in FIGS. 10 and 11, the data rate at the time of reading the information is lower than that in the case where the two-track jump is performed in FIGS. Does not occur.
In other words, when the error rate is high such that the error rate X is greater than the error rate E1, the burst error correction in the error correction circuit 29 does not function effectively, so that reading is performed such that an information missing section does not occur. The operation was performed.

In the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 2, the recording information is divided by the grating lens 104 in order to read the recording information from three adjacent recording tracks. Although three information reading beams are irradiated on each recording track, the present invention is not limited to such a structure. For example, three independent information reading means may simultaneously read recorded information from three recording tracks.

Further, the number of simultaneous readings is not limited to three, and the present invention is applicable to a configuration in which recording information is simultaneously read from N (N is an integer of 2 or more) recording tracks. . At this time, (N-1) track jump is performed in step S9 in FIGS. 2 and 7, and (N-2) track jump is performed in step S13 in step FIG.

That is, in the first embodiment, when the reading error rate X is smaller than the error rate E1, the information reading operation for one rotation of the disk up to the disk radius line DL and (N-1) ) The track jump operation is alternately and repeatedly executed. In the second embodiment, when the reading error rate X is smaller than the error rate E1, the disk is not re-read until the recording track that has already been read before one rotation of the disk is read. The information reading operation for one rotation and the (N-1) track jumping operation are alternately and repeatedly executed, and the reading error rate X becomes equal to the error rate E1 described above.
If it is larger than the above, the information reading operation for one rotation of the disk and the (N-2) track jump operation are alternately repeated until the recording track which has already been read before the rotation of the disk is read again. Do it.

In the second embodiment, when the read error rate X is larger than E1, that is, when the read error rate is extremely high, the track jump or jump operation of (N-2) or less is performed. May not be performed.
In the first and second embodiments shown in FIGS. 2 and 7, the error rate X is measured every time one track jump operation is completed and the next reading operation is started. However, the present invention is not limited to such a configuration. For example, it may be carried out only at the time of disk exchange, or may be carried out periodically by a timer interrupt or the like.

As described above, in the recorded information reading method according to the present invention, the information data read by the information reading means for simultaneously reading the recorded information from each of N (N is an integer of 2 or more) recording tracks includes: When the reading error is relatively small (smaller than the error rate E1), the reading operation for one rotation of the disk and the (N-1) track jump operation are alternately performed by the information reading means. On the other hand, when the read error rate is relatively high (greater than the error rate E1), the reading operation for one rotation of the disk by the information reading means and (N-2)
The following track jump operation (including the case where no track jump is performed) is alternately performed. By performing such an operation, simultaneous reading from each of the N recording tracks formed on the recording disk is realized.

Thus, according to the present invention, it is possible to simultaneously reproduce recorded information from N recording tracks without deteriorating the information reading accuracy, thereby achieving high-speed reproduction.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a recorded information reproducing device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a reproduction operation subroutine flow according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a reading operation when an error rate X is smaller than an error rate E1.

FIG. 4 is a diagram illustrating a reading operation when an error rate X is smaller than an error rate E1.

FIG. 5 shows an error rate X in each case where the total burst error length is the number of lines of an ECC block of 0, 4, 6, or 8, and an error rate of correction information data after error correction processing by an error correction circuit 29; It is a figure which shows the correspondence of.

FIG. 6 is a diagram showing a configuration of a recorded information reproducing device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a reproduction operation subroutine flow according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating a reading operation when the error rate X is smaller than the error rate E1.

FIG. 9 is a diagram illustrating a reading operation when the error rate X is smaller than the error rate E1.

FIG. 10 is a diagram showing a reading operation when the error rate X is larger than the error rate E1.

FIG. 11 is a diagram illustrating a reading operation when the error rate X is larger than the error rate E1.

[Description of Signs of Main Parts]

 23 Recording Disk 24a-24c Information Data Demodulation Circuit 25 Address Extraction Circuit 27 Reread Detection Circuit 28 Slider Mechanism 29 Error Correction Circuit 31 ROM 32 CPU 35 Pulse Generator 100 Pickup

Claims (10)

[Claims] 1. A recording information reading method for a recording information reproducing apparatus for obtaining reproduction information data by reproducing recording information recorded on a recording disk, wherein the recording information reproducing apparatus is formed on the recording disk. Information reading means for simultaneously reading recorded information from each of the N (N is an integer of 2 or more) recording tracks to obtain N read signals; Error correction means for making the reproduced information data an error-corrected data. If the number of errors is small, a read operation for one rotation of the disk by the information read means and an (N-1) track jump operation are performed. A recorded information reading method in a recorded information reproducing apparatus, wherein the method is repeatedly executed alternately. 2. The method according to claim 1, wherein when the number of errors is large, a read operation for one rotation of the disk by the information reading means and a track jump operation of (N-2) or less are alternately repeated. A recorded information reading method in the recorded information reproducing apparatus described in the above. 3. A recording information reading method in a recording information reproducing apparatus for obtaining reproduction information data by reproducing recording information recorded on a recording disk, wherein the recording information reproducing apparatus is formed on the recording disk. Information reading means for simultaneously reading recorded information from each of the N (N is an integer of 2 or more) recording tracks to obtain N read signals; Error correction means for using the error-corrected data as the reproduction information data, determining a data error rate in the read signal, and when the data error rate is smaller than a predetermined error rate, Recording information characterized in that the reading means alternately repeats an information reading operation for one rotation of the disk up to one disk radius line and an (N-1) track jump operation. Reading method. 4. A recording information reading method in a recording information reproducing apparatus for obtaining reproduction information data by reproducing recording information recorded on a recording disk, wherein the recording information reproducing apparatus is formed on the recording disk. Information reading means for simultaneously reading recorded information from each of the N (N is an integer of 2 or more) recording tracks to obtain N read signals; Error correction means for using the error-corrected data as the reproduction information data, obtaining a data error rate in the read signal, and when the data error rate is smaller than a predetermined error rate, disc 1 The information reading operation and the (N-1) track jump operation are alternately and repeatedly performed until the read signal already read before rotation is read again, and the data error rate is equal to the predetermined error. If it is larger, the information read operation until the read signal already read before one rotation of the disk is read again and the track jump operation of (N-2) or less are alternately and repeatedly executed. Information reading method. 5. The apparatus according to claim 1, wherein said error detection is a random error detection, and said error correction means corrects a burst error of a line length corresponding to a data error rate in said read signal. The recorded information reading method described above. 6. A recording information reproducing apparatus which reproduces recording information recorded on a recording disk to obtain reproduction information data, wherein N (N is an integer of 2 or more) formed on the recording disk. Information reading means for simultaneously reading recorded information from each of the recording tracks to obtain N read signals, detecting an error occurring in the read signal and correcting the error to obtain the reproduced information data Error correction means; and control means for alternately and repeatedly executing a reading operation for one rotation of the disk and an (N-1) track jump operation by the information reading means when the number of errors is small. Recording information reproducing device. 7. The control unit according to claim 1, wherein when the number of errors is large, the information reading unit alternately repeats a reading operation for one rotation of the disk and a track jumping operation of (N-2) or less. The recorded information reproducing apparatus according to claim 6, wherein 8. A recording information reproducing apparatus for reproducing recording information recorded on a recording disk to obtain reproduction information data, wherein N (N is an integer of 2 or more) formed on the recording disk Information reading means for simultaneously reading recorded information from each of the recording tracks to obtain N read signals, detecting an error occurring in the read signal and correcting the error to obtain the reproduced information data Error correcting means; error rate measuring means for obtaining a data error rate in the read signal; and if the data error rate is smaller than a predetermined error rate, the information reading means extends up to one disk radius line. A recorded information reproducing apparatus, comprising: a control unit for alternately and repeatedly executing an information reading operation for one rotation of a disk and an (N-1) track jump operation. 9. A recording information reproducing apparatus for reproducing recording information recorded on a recording disk to obtain reproduction information data, wherein N (N is an integer of 2 or more) formed on the recording disk Information reading means for simultaneously reading recorded information from each of the recording tracks to obtain N read signals, detecting an error occurring in the read signal and correcting the error to obtain the reproduced information data Error correction means; error rate measurement means for obtaining a data error rate in the read signal; if the data error rate is smaller than a predetermined error rate, the read signal already read before one revolution of the disc is read again. While the information reading operation until reading and the (N-1) track jumping operation are alternately and repeatedly executed, if the data error rate is larger than a predetermined error rate, the data is read out. Click 1
A recorded information reproducing apparatus, comprising: a control unit that alternately and repeatedly executes an information reading operation until a read signal already read before rotation is read again and a track jump operation of (N-2) or less. 10. The error detection is a random error detection, and the error correction means corrects a burst error of a line length corresponding to a data error rate in the read signal. The recorded information reproducing apparatus according to the above.